Court tells private investigator he must identify 'News of the World' executives who asked him to intercept voicemails

Glenn Mulcaire, the private investigator at the centre of the phone-hacking affair, will be forced this week to reveal the identities of the News of the World employees who hired him to intercept the voicemails of public figures.

Mulcaire will have to submit to the court the names of the people who engaged him to hack the phones of model Elle McPherson, publicist Max Clifford, football agent Sky Andrew, Liberal Democrat deputy leader Simon Hughes, chief executive of the Professional Footballers' Association Gordon Taylor, and one of its legal advisers, Jo Armstrong.

The order came about as the result of a civil case brought against the investigator by Steve Coogan, whose lawyers argued in February that if it were proved that the paper had instructed Mulcaire to hack into the phones of six public figures, it would show the hacking had been taking place on an industrial scale.

Mulcaire applied to the Court of Appeal to try to overturn the order, but was refused permission by Lord Justice Toulson. He is also suing News International, publisher of the News of The World, in an attempt to force the company to pay his legal bills.

James Murdoch, who has managerial responsibility for News International, told the House of Commons media select committee currently investigating phone hacking on Tuesday that News International had paid "approximately £246,000" to Mulcaire's lawyers before cutting off payments in July.

Evidence provided to the committee also shows that News International paid Mulcaire £80,000, plus £5,000 in legal costs, in June 2007 to settle an employment tribunal action he launched against the company.

The publisher also had to pay out a "healthy six-figure sum" last week in an out-of-court settlement with the actress Leslie Ash and her husband, Lee Chapman. Although they have not disclosed the exact figure, a statement released by the couple says they have received "an appropriate sum by way of compensation".

Meanwhile, concerns are growing at New York-based News Corporation, the owner of News International, that emails uncovered during the 2007 phone-hacking investigation might expose the American business to litigation.

Thousands of News of the World emails were assembled after the scandal erupted four years ago, when the reporter Clive Goodman and Mulcaire admitted intercepting royal aides' phone messages.